1954 10hp Johnson problem at high RPM's

[gmarshall43]

I was running my 1954, 10hp motor last week. It starts up and idles great. It will run normally at low to mid throttle. But when I go to full throttle, the motor seems to go into neutral as the motor's RPM's run really high and I'm not going any where. And the gear shift level still shows it is in forward. What is the problem?<br /><br />Thanks

 

[Joe Reeves]

Re: 1954 10hp Johnson problem at high RPM's

Usually that problem is due to the following. <br /><br />Either the engine's mounted too high (prop out of water at planing speed) or the propeller has spun its hub (slipping).

 

[petrolhead]

Re: 1954 10hp Johnson problem at high RPM's

If it's revving high and he's not going anywhere it's unlikely the prop is out of the water, spun hub is my guess.

 

[rwise]

Re: 1954 10hp Johnson problem at high RPM's

I'll go with the spun hub, but, check the shear pin also. I am not sure but I think some of the older engines had spring drive on the input shaft just above the lower unit.

 

[gmarshall43]

Re: 1954 10hp Johnson problem at high RPM's

Is a spun hub an easy fix and can I get parts for it?<br /><br />Thanks for the help.

 

[rwise]

Re: 1954 10hp Johnson problem at high RPM's

Just remove it and take it to a "prop shop" they should be able to fix it up for you.